In the computer systems known as the IBM® Power®7 Systems or POWER®7 computer system design. The POWER®7 computer system is an announced prospective successor for the Power®6 computer system. United States patent application US2008/307287A1 entitled: SYSTEM AND METHODS FOR RECOVERY FROM HARDWARE ACCESS ERRORS, filed Jun. 7, 2007 under application Ser. No. 11/759,331, by Daniel M. Crowell et al, and assigned to International Business Machines Corporation, the assignee of this application, is incorporated herein fully by reference, and describes material used in the Power®6 computer system. The Power®7 computer system is expected to be compatible with the Power®6 computer system and has a marking store that can be read and written by firmware through IBM's SCOM (Scan Communication). This Scan Communication is an inter-chip communication protocol like that described in U.S. Pat. No. 7,392,350, issued Jun. 24, 2008, entitled: METHOD TO OPERATE CACHE-INHIBITED MEMORY MAPPED COMMANDS TO ACCESS REGISTERS, by James S. Fields, Jr. et al, also assigned to International Business Machines Corporation, the assignee of this application. U.S. Pat. No. 7,392,350 is incorporated herein fully by reference. As system design improves, integrating the hardware and firmware used becomes difficult, and this application addresses improvements we have made to the Power®7 computer system having a marking store to protect the marking store during high speed operations of the system.